Welcome to the fourth of RotoBaller’s six-part midseason dynasty league prospect update! Today I am looking at the American League East Division, analyzing which prospects are going to be the best long-term assets for fantasy owners in dynasty leagues.

Just to be clear, this is an overview of the entire division, meaning prospects from all five teams will be discussed here. I am not going to delve into the value of each prospect in the teams’ respective Top 10 lists and only focusing on the elites of the elite, but we’ll do a more advanced look into each of the teams’ prospects during the offseason. And of course, if at any point you have any prospect related questions, you can hit me up @EdwardSutelan on Twitter.

By the way, if you are interested in more MLB prospects columns, head on over to our 2017 fantasy baseball rankings dashboard. Throughout the offseason, you will find the rest of our team prospect breakdowns, fantasy baseball prospect rankings, tiered positional rankings, keeper values articles, and more - all in one easy place.

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NL East Top Prospects for Dynasty Leagues

Today I am beginning my list of prospect systems in the NL divisions. I have already covered the AL East, Central and West. Later, I will delve into the NL Central and NL West. To read more about my prospect coverage, click here.

Top Overall Talent: Ronald Acuna (OF, ATL)Top Prospect who won’t debut in 2017: Ronald Acuna (OF, ATL)
I’m probably going to catch a lot of heat for putting Acuna above Robles, but I want everyone to know that it is really more like 1a Acuna and 1b Robles. And don’t worry, I’m going to sufficiently explain why I believe Acuna is the best prospect. For starters, Acuna is half a year younger than Robles and is already at Double-A while Robles remains at High-A. Not only is Acuna at a level higher, but his numbers across the board are better with the exception of strikeout rate. A 19-year-old with a .318/.368/.507 slash line with nine home runs and 18 stolen bases in 56 games at Double-A stands out a bit more than a 20-year-old with a .302/.388/.524 slash line with seven homers and 14 stolen bases.

The other major reason for Acuna’s placement being a spot higher is that I have heard more scouts that believe in Acuna’s power than Robles’ pop. Though Robles is probably faster, the more likely player to hit .300 with a 20/20 season is Acuna (though both have a decent chance to reach that point). If you’re debating between the two prospects, the safer of the two prospects is probably Robles who has superior plate discipline. But the guy with more apparent upside in this writer’s eyes is Acuna. And with a fine line splitting the two prospects, I’m going to lean with the higher upside.

Top Prospect to Debut in 2017: Amed Rosario (SS, NYM)
Acuna and Robles may be 1a and 1b, but then that would really put Rosario at 1c because he too was very close to the top spot. The New York Mets’ top prospect is one of the best contact hitters in the minors, with many scouts believing him to be a future .300+ hitter in the majors. Though he has never been a great power hitter, Rosario has scouts believing in his raw power upside with some seeing a possible 15-homer hitter. Couple that with his already well above-average speed and you’ve got a potential 15/20 shortstop with a .300+ batting average. He is also a potential Gold Glover at the position, which will help him stay at shortstop longterm. And with the New York Post reporting that he could be up on Aug. 1 after some trades go through, owners may have a chance to reap the Rosario rewards in 2017.

Biggest Boom or Bust: Victor Robles (OF, WAS)
I need to make sure that I clarify that by no means by I mean to imply that I think Robles is going to be a bust. But this “Boom or Bust” superlative here for Robles means that he has the chance to either be one of the game’s most elite players, or he might just be a speedster with a great batting average and no power. Manny Margot is a solid player, but not an elite player by any means. Some have brought up the concern that Robles could just be another Margot if he does not develop any power, which some believe he will develop. If he develops the power, he has a chance to be one of the game’s elites. If not, he has the chance to be a really great player.

Biggest Sleeper: Carter Kieboom (SS, WAS)
First-round picks are rarely too overlooked, but Kieboom has not received nearly as much notoriety as he deserves. He is a 19-year-old with a .333/.398/.586 slash line with six homers and a pair of stolen bases at Class-A so far this season. He has also posted a respectable 8.1 percent walk rate and 20.3 percent strikeout rate. He could be a .280 hitter with at least 15/15 seasons with the potential for more. The biggest question remaining will be whether he is a shortstop or third baseman. Regardless, his bat should carry him through the minors and onto fantasy rosters.

Top Prospect Hitters

Best Power Hitter: Dylan Cozens (OF, PHI)
There’s a lot of guys with raw power in this division, but the guy with the most game power has to be Cozens. The 40 homers last season at Double-A Reading was mostly a product of one of the most hitter-friendly MiLB environments, but he has continued to flash that power at Lehigh Valley. Though neither the speed nor batting average have carried over from last season, Cozens has 21 homers already in 87 games. Scouts believe the power is for real, though questions remain about whether or not he can cut down on the strikeouts. But if he makes it to the majors, the power should be able to carry over and owners should be able to count on plenty of home runs.

Most Likely to Hit over .300: Amed Rosario (SS, NYM)
As discussed earlier, Rosario has a quick, smooth swing that is geared for making loads of hard contact. He is more of a gap-to-gap, line drive hitter right now, but some think more home run power will come later. But those who are buying into Rosario are buying into him because they are betting on a guy who will compete for batting crowns on an annual basis, and Rosario should do exactly that.

Best Burner on the Bases: Roman Quinn (OF, PHI)
If Quinn had been able to stay healthy, we could be talking about him like a Billy Hamilton with a better bat. Few prospects have received a near-unanimous 80-grade in speed, but Quinn is one of them. Though he has never played in 100 games in any single season since being drafted in 2012, Quinn has swiped at least 29 bags in every season except for this one so far. The strikeouts are a bit of an issue, but he makes enough contact to at least post a .260-.270 batting average in the majors. The key now will be to stay healthy.

Top Prospect Pitchers

Strikeout Machine: Sean Newcomb (SP, ATL)
Strikeouts have never been an issue for Newcomb. But control has been. With an upper-90s fastball and near-elite curveball, Newcomb has always missed bats at an incredibly high rate. His strikeout rate typically sits around 30 percent on an annual basis, and though he’s only striking out 21.4 percent of opposing batters in the majors right now, he does have three games already with seven strikeouts or more. The walks remain an issue, and though he has displayed more control in the majors so far, owners will need to wait and see if his newfound control is for real. If he can maintain the solid control, he has the stuff to be a future ace. Even if the walks come back, his strikeout upside makes him a pitcher worth owning in keeper leagues.

Best Command: Tom Eshelman (SP, PHI)
Strikeouts have never been a major part in Eshelman’s game. But control has been. It is rare that scouts give someone a grade of 70 for control, but that’s exactly what scouts give to Eshelman. Since joining the Philadelphia Phillies’ system, the highest walk rate he has posted in a season was 6.1 percent last season at Double-A. Now at Triple-A, he owns a minuscule walk rate of 3.0 percent. While in college at Cal State Fullerton, he set the NCAA record for lowest walk rate in Division I history, allowing only 0.43 walks per nine innings. That’s pinpoint. He has only once posted a strikeout rate above 20 percent, so it’s unlikely that will be a big part of his game in the majors, but with his control, he has a high floor and should be able to reach the majors as a backend of the rotation starter.